


Field Testing

by centreoftheselights



Category: Ghostbusters (2016)
Genre: Aftercare, Bondage, Dildos, Established Relationship, F/F, Fucking Machines, Light Dom/sub, Misuse of Engineering Degrees, Multiple Orgasms, Nipple Play, Overstimulation, Plot What Plot/Porn Without Plot, Summer Scorcher 2016, Vibrators
Language: English
Status: Completed
Published: 2016-08-26
Updated: 2016-08-26
Packaged: 2018-08-11 05:13:11
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,420
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7877839
Author URL: https://archiveofourown.org/users/centreoftheselights/pseuds/centreoftheselights
Summary: <blockquote class="userstuff">
              <p>“You built a <i>sex machine</i>?”</p>
            </blockquote>





	Field Testing

**Author's Note:**

> My main submission for [Summer Scorcher 2016](http://femslashrevolution.tumblr.com/tagged/Summer%20Scorcher%202016)!
> 
> (With thanks to [Oh Joy Sex Toy](http://ohjoysextoy.com/), which was very useful for reference.)

“I've got something to show you. Don't freak out.”

Coming from Holtzmann, no words were more likely to inspire terror in Erin. She had come over expecting to spend the day relaxing with her girlfriend, but suddenly she was on red alert. She glanced around the apartment nervously, trying to guess which of the half-dozen projects lying around the room was most likely to explode.

“C'mon.”

Holtz led the way into her bedroom. As soon as Erin walked in the door, her eyes were drawn to a massive machine which occupied at least half of the small space. It was part contraption, an unintelligible mass of pistons and chrome, and part hospital bed, a long flat board with leather cuffs on it as though someone was supposed to be strapped there. It took several seconds before Erin's brain resolved the all-too-familiar shape of the machine's business end…

She blushed.

“You built a _sex machine_?” she asked, lowering her voice to an embarrassed hiss even though there was no-one around to hear.

“Pretty neat, huh?” Holtz grinned.

Then the other shoe dropped.

“Oh,” Erin said. “Oh no. Nuh-uh, no way.”

Holtz's grin only got wider.

“It's completely safe,” she said. “Nothing in there that I wouldn't put inside -” She paused for a moment, just long enough for both of them to remember some of Holtz's more colourful stories - “you. Not even nuclear – although it still packs a punch.”

Erin could feel her pulse quickening, and in spite of herself she can't help wondering what it would be like. Holtzmann was an engineer right down to the core, and there were times when it seemed like she viewed sex as just another set of equations to be solved – friction, pressure, force. That tendency had led to a lot of new experiences for Erin, most of them thoroughly enjoyable. So perhaps this was the logical next step…

“What _exactly_ does it do?” she asked.

Holtzmann drummed her fingers on the machine.

“I _could_ tell you,” she said. “Or, I could show you.”

A thrill of anticipation shot down Erin's spine.

“Look,” Holtz said. “I'm not going to make you -”

“I'll do it,” Erin said, impulsively.

Holtz lit up, beaming like a kid on Christmas.

“OK, so, what do I -?”

Erin's question was cut off by Holtzmann kissing her. For the first time since this conversation had began, she felt like she knew what she was supposed to be doing. She wrapped her arms around Holtz's waist and moaned as Holtz pressed a line of kisses down her throat, the faintest scrape of teeth in each one.

As she made out with her girlfriend, Erin felt the tension drain out of her. She reminded herself that this exercise was supposed to be fun – Holtz's idea of fun, at least, which was a little strange and definitely blurred the lines between pleasure and pain, but had never actually caused either of them serious injury. And the thought of that machine – the gears, the circuits, those _leather straps_ – had Erin's heart pounding in her chest. Once, that would have been fear, but now it was making her wet, which was probably a side effect of dating Holtz for any significant length of time.

Holtz's hands went to the small buttons on Erin's shirt, slowly teasing it open – a concession to her nerves, because normally Holtz lost patience and tore her clothes off, much to Erin's annoyance. It didn't take long until her shirt was gone, and Holtz was sucking a hickey into the exposed curve of Erin's breast. Erin whimpered, and moved her hands towards the hem of Holtz's crop top, but she was batted away. Holtz got like that sometimes, wanting to give attention but not get it, and Erin had learned to accept that, although the full force of that spotlight was sometimes overwhelming.

Holtzmann made quick work of Erin's bra and pants, then pushed her backwards towards the double bed. Erin collapsed onto her back as Holtz leaned over her, grabbing Erin's panties in her teeth and pulling them off.

Erin had a moment of dizzying realisation that she was now stark naked and sprawled out on the bed while a fully-clothed Holtzmann stood over her. But then Holtz dropped to her knees and pulled Erin's legs over her shoulders, and Erin wasn't doing much thinking at all.

Sometimes, sex with Holtz was slow and unhurried, hours of gradually building pleasure. This wasn't one of those times. Holtz dove in tongue-first, smoothing long licks over Erin's inner lips and sucking softly on her clit. Erin knotted her hands in the sheets and groaned as Holtz's tongue found its way inside of her, pressing her open and leaving her gasping for more.

“Oh God, Holtz, don't stop!”

Holtz pulled back, smirking up at Erin from between her legs.

“Are you feeling warmed up yet?”

Erin turned her head to look at the machine, waiting for her in the corner. Her heart was thudding in her chest, and all of her doubts had been chased away by lust.

“Let's do this,” she said, struggling to her feet. “Uh, are you sure it's all OK?”

“All the attachments are one hundred per cent body-safe silicone,” Holtz reassured her. “And freshly sterilised. If you'll take your position...”

Holtz gestured to the bed end of the contraption, and Erin lay down. Although the platform was narrow, it was surprisingly comfortable.

“Are all there straps really necessary?” she asked.

“The arm ties are _purely_ recreational.” Holtz winked in a way that made Erin squirm. “But the leg straps are an important safety feature.”

“I thought you didn't believe in safety features.”

“I don't believe in them when they can be replaced by common sense,” Holtz said. “But if this baby does her job, common sense will be going out the window. If you'll allow me?”

Erin let Holtz pull her ankles apart, strapping each one to stirrups on the sides of the machine so that Erin's knees were slightly bent and spread open wide. When she was satisfied those straps were secure, she did up three more straps over her waist and each of her thighs. When Holtz was done, Erin couldn't move her hips an inch in any direction.

“You ready to get started?”

“I – I think so.”

Hearing the tremor in Erin's voice, Holtz moved to stand over her, cupping Erin's face with one hand.

“I'm not going to do anything you don't want,” she said. “Trust me.”

Erin took a deep breath.

“I do.”

Holtz smiled. “Then let's get started.”

She picked up a control pad that looked like something from a sci-fi show, with more lights and dials and levers and buttons than Erin could imagine uses for. She sat herself cross-legged on the main bed like a kid about to watch a fireworks show.

Then she flicked a switch, and the machine whirred into life. A red light appeared, laser beams scanning back and forth across Erin's inner thighs, making her feel like a specimen under a giant microscope. Then there was a high-pitched beep, and the machine began to move.

To her surprise, the large phallic object she had seen while the machine was dormant didn't move towards her. Instead, it withdrew into the machine, which proceeded to make a number of loud clunking sounds.

“Since it's your first time, I think we'll go with two,” Holtzmann announced, jabbing at buttons on the control pad.

“Level two?” Erin asked. “That doesn't sound too bad.”

“Two orgasms,” Holtz clarified.

“Uh.” Erin wavered. She knew from long experience that she was far from the fastest in that department. While she had had multiple orgasms before – Holtzmann had seen to that – they had always taken a long time to achieve.

“Are you sure that's the best idea?”

Holtz glanced up at her.

“You know, you're going to get a crick in your neck if you don't lie back.”

Erin sighed, and lowered her head back against the pillow, waiting for the machine to get going.

It didn't take long. The first touch of cool silicone against the heat of her vulva made her start, and she instinctively tried to wriggle away, but the straps held her tight. This attachment wasn't a dildo, but something that lay across her entire vulva at once, pressing her lips open and resting gently on her clit. The sensation of having it there was strange, but not exactly arousing.

She was just about to ask what the point of this was when it started to vibrate.

Erin threw her head back against the pillow, her hands clenching into fists at her sides. A rush of blood filled her ears, and she pushed against the restraints again, harder, but they still held firm. The rumbling pressure against her vulva never stopped, and when she finally caught her breath again, she could feel beads of sweat on her forehead.

“Everything good?” Holtz asked. “You've never made that noise before.”

“Fuck -” Erin gasped. “Yes, fuck. Yes, good. Keep going.”

As she adjusted to the vibrations, she slowly realised that they weren't constant. Waves of intensity were pulsing slowly up her lips, breaking on her clit. She found herself breathing in time with the waves, the straps pressing into her as her hips rolled unconsciously into the sensation. Although her hands were free to move, it was all she could do to grasp tight to the edges of the bed, her eyelids fluttering, feeling as though she was floating untethered in space, lost in a wash of sensations.

“You ready for some more?”

Holtz apparently didn't wait for an answer. The vibrations shifted, becoming faster and more intense, but drawing down, away from her clit. Erin made a noise in protest, but before she could find words a new attachment pressed against her in place of the vibrations. Unlike the broad shape before this one had hard edges, which pressed around her clitoris without providing any direct pressure.

Then it started to suck.

Forming a vacuum seal around her clit, the sudden tug made Erin swear out loud. The sucking motion began pulsing in time with the vibrations around her vulva, a constant change that made it impossible to get used to the sensations. The cup was vibrating too, or perhaps the vibrations from the other device were resonating through her, the combination so intense that it was on the edge of painful, like a fire burning right at the heart of her.

Erin could feel her orgasm approaching from a distance, the speed of it shocking her. She knew it wouldn't take much more of this before she was tipped over the edge.

But Holtz had always been more ambitious than that with her creations.

Erin felt the vibrations rumbling across her labia split open, breaking into two segments that pushed her lips apart. Between the two, something nudged against her opening, pressing gently inside before pulling out again. It wasn't particularly wide, but it entered her inch by agonising inch, its shallow thrusts making its slightly curved shape rub against her entrance with just the right sort of pressure. She heard herself moaning softly with every thrust, wanting it deeper inside of her.

But before things got that far, the dildo began to move.

At first Erin thought is was only that the angle of the thrusts had shifted slightly – but then the entire shaped _coiled_ inside her, pressing outwards and curving around, then slowly unravelling back to it's previous shape. The tip drew long arcs across her insides, twirling in a complete three-sixty, then zig-zagging most of the way out of her before thrusting back in.

It was like nothing Erin had felt before. Heat prickled across every inch of her skin, the straps burning against her ankles. She was alternately panting for breath and keening, high and inarticulate, unable to make her voice express anything but her desire for more. She was so close to orgasm that she could taste it, but somehow it wasn't quite enough to push her to her completion. Her head tossed against the pillow, thrashing one way and the other, her eyes open but unseeing -

And then her gaze locked on Holtzmann, sat on the bed, holding the control pad. Her hands flew over the buttons and dials as she played her symphony on Erin's insides, her tongue stuck out of her mouth in concentration. She glanced up at Erin, and their eyes met for a moment before Holtz jabbed at a button on the pad, and the dildo curved itself up to rub across Erin's G-spot, once, twice -

Erin Gilbert shook herself apart.

The orgasm hit her like a freight train, her back arching off the bed so hard that only the straps kept her from falling onto the floor. It felt less like fireworks and more like dynamite – harsh, brutal, devastatingly powerful, awe-inspiring. Aftershocks rippled through her again and again, sending her writhing back and forth, until finally the light behind her eyes faded from blinding to bearable, and she could think in words again.

“Fuck shit fuck Holtz fuck damn.”

“Well, that was one for the spank bank.”

Erin opened her eyes to see Holtzmann watching her with an expression halfway between awe and lust. A crooked smile curved its way across her face as she basked in the glow of endorphins and Holtz's attention.

“So,” Holtz asked. “Are you ready to start round two?”

Erin realised that Holtzmann had turned down the stimulation to allow her a brief recovery. The suction on her clit had stopped, and the dildo had stilled inside her, although the vibrations were still going strong.

She sucked in a deep breath.

“Hit me.”

“That's my girl,” Holtz said. “Let's see...”

The vibrations began to slowly ramp up in intensity again. After a few seconds, the cup over Erin's clitoris began suckling at her once more. However, what had before been pleasurably overstimulating had now tipped over the threshold into pain.

Erin hissed through her teeth.

“No, no, too much -” She whimpered. The suction stopped immediately, the vibrations dialling back down to nearly nothing.

“What's wrong?” Holtzmann asked.

“The suction cup,” Erin answered, more specific now she was able to catch her breath. “It's too much, I'm too sensitive -”

Holtzmann face-palmed. “Of course. Don't worry, we can try something else. You still good?”

Erin nodded. The brief pause had cleared her mind for a few moments, her lust fading in the wake of her first orgasm. But even momentarily sober, she didn't want to stop. Her shame had faded away, and she found that she loved this: being strapped here, helpless, entirely at the mercy of Holtzmann and one of her contraptions. Trusting that Holtz would take care of her, and knowing that she didn't have to do anything but experience her own pleasure… It wasn't something she'd want to do every day, but right now, there was nowhere she'd rather be but here.

Just as this thought hit her, the suction attachment rolled back into the machine, and something new reached out to replace it. After a few seconds of waiting, the replacement made contact with Erin's clit, making her gasp. Unlike the hard, smooth edges of the suction cup, this attachment was soft yet firm, rubbing in gentle circles over her clit. It felt like a hand, and it was too easy to imagine Holtz's fingers there, gently coaxing the sounds of pleasure from her mouth.

Then it started vibrating, a soft and rumbling sensation that faded in and out of intensity as the pressure on the device changed.

“Oh, yeah,” Erin said. “Just like that. Don't stop.”

“I wasn't planning on it.”

Erin could feel all the tension drain out of her as her arousal slowly returned. She let her tired muscles rest, breathing deep through her mouth in between low, appreciative moans. Her head rolled back against the pillow behind her, and her hands itched to do something. Knowing that reaching down to where the machine was working was unwise, she turned her attention in the other direction, sucking two of her fingers deep into her mouth to dampen them, and then using them to rub slow circles around one of her nipples.

“Fuck,” she heard Holtz say. Erin opened her eyes, smiling lazily at the undisguised lust on her girlfriend's face. “That's the hottest thing I've ever seen.”

“I bet you say that to – ooh, all the girls.”

Erin pinched her nipple, rolling it between her fingers, feeling the jolt of sensation all the way down her spine.

“If I do, I'm a liar. You're putting them all to shame.” Holtz bit her lip. “Shit, next time I'm going to have to film this.”

Erin arched her back, bringing her free hand up to cup her other breast.

“So there's going to be a next time?”

“Baby, there will be as many times as you want. Although I might make a few… upgrades.”

“Mmm…”

Erin lost track of the conversation, her mind growing hazy again as her arousal picked up speed. She was starting to want more, feeling her pussy clench and tighten around the dildo that was still inside her – but the dildo's ministrations and her first orgasm had left her stretched out, too loose for it to fill her in the way she wanted. It took all of her focus not to simply thrust three fingers inside herself and start pumping.

“Mmm, Holtz?” Erin said instead. “Will you hurry up and fuck me?”

“Oh, is that how it is?” Holtz said with a grin. “Well, in that case…”

The dildo pulled out of Erin smoothly, so wet that there was almost no resistance. She groaned at the emptiness inside her.

“ Don't worry,” Holtz said. “I've got a new friend for you to meet.  That is, if you think you're ready for her.”

H oltz dialled a few buttons on the control pad, and the  machine sent a new attachment out towards  Erin. But this time, nothing made contact with her.

“What do you think of this?”

Craning her neck, Erin could see that  the machine was holding the attachment up for her approval.  It was a black dildo,  thick enough that Erin  knew she  couldn't have wrapped her hand around it , with  a bulbous head  and ridged sides.  It was as large as any of the toys they had played with before, and this time it would be attached to a powerful motor, with no way for Erin to  control the pace.

S he had never wanted anything  inside of her  more.

“ Yes,” she said,  letting her head fall back again, tired from the effort. “Please, Holtz. I need it  _ now _ .”

“ Okay then, I'll give it to you,” Holtz said. “But I'm going to take it nice… and… slow…”

Erin let out a groan of frustration, which soon turned to a moan of pleasure as she felt the dildo pressing against her entrance.  As promised, i t pushed inside her maddeningly slowly, stretching her open  in exactly the way she needed.  Erin was almost salivating of the thought of how full she would feel with the dildo fully inside her.

S he felt a sudden release of pressure, and knew that the head was now fully inside her,  and her patience felt stretched to its limit.

“C'mon, Holtz, please…”

But instead of fucking into her like she wanted –  _ needed _ –  instead, the dildo continued to press forward in slow, shallow thrusts.

“ Fuck, fuck, fuck,” Erin panted with each thrust. “C'mon, please, I want, I need, please, I – ohhhh…”

S he broke off her litany into a moan  as the dildo started to vibrate inside of her,  pulsing on and off in time with the thrusts.  She could feel the sensation of it all the way from her stretched lips to the  rounded  tip as it thrust its way inside of her inch by inch.

It seemed to take an eternity. But finally, the dildo pressed so far into her that it could go no deeper – so far that she could feel it, right in her core, the wonderful pressure of it against her insides and the vibrations strong enough to make her eyes roll back with pleasure – and then it stilled. After a few seconds of waiting, the toy motionless inside of her, Erin shot a look at Holtz, only to find that her girlfriend was watching her with an expectant glint in her eyes.

“Hold onto something,” Holtz said.

Obediently, Erin dropped her hands from her chest, winding her wrists around the untied leather straps at her sides.

Holtz nodded approvingly, and her hands began to fly over the controls. Erin began to feel the dildo pulling out of her, quick and smooth, the ridged sides rubbing pleasurably against her as it went. When only the head was left inside of her there was another pause, and Erin felt her breath catch in her throat, her attention laser-focussed with anticipation -

And then the dildo slammed back into her.

A tidal wave of sensation swept over her – not pleasure or pain, but pure intensity of feeling. Erin felt weightless, felt like she was falling, felt nothing at all but the fire burning in her pussy.

And then it happened again. And again. The machine thrust into her at a punishing pace, flooding her with stimulation. Slowly, she began to be able to pick apart sensations – the sharp edge of the leather cuff held tight in her hand, the frantic pace of the vibrator rubbing her clit, a trickle of moisture down her cheek that could have been sweat or tears. Her mouth gaped open, but she could hardly tell if she was making sound or simply gasping for air.

It was too much.

She wanted to come so badly – needed to, could hardly believe she hadn't already – but somehow, the orgasm evaded her. It felt as though she had passed through that point of pleasure and into some new, unexplored territory. Holtzmann had stripped her bare like an exposed nerve, and now she could do nothing but _feel._ Reaction without action. An infinite void of pure stimulation.

“Babe.”

Erin blinked her eyes open to see Holtzmann standing over her, looking down at her. She wasn't entirely sure where she was any more, but she knew this was right. Holtz was the only one who could take her apart like this.

“You're so beautiful,” Holtz told her, trailing her fingers lightly over the muscles in Erin's stomach, which rippled and flexed with each thrust of the machine. “What do you think of my cock?”

The words made Erin groan out loud, feeling as though every thrust was Holtz inside of her, pushing her closer and closer to the edge.

“That good huh?” Holtz asked, teasingly. “Is it going to make you come?”

Erin whined.

“Can't,” she panted, desperately. “Holtz, please…”

“Shh, don't worry babe.” Holtz stroked a hand through Erin's hair. “I've got you. I'm here. Just relax and let me help.”

At first, Erin didn't understand her words. But then Holtz got to her knees beside the bed, leaning over to suck one of Erin's nipples into her mouth.

That was enough. As she felt Holtz's tongue flick over her breast, Erin could sense that her orgasm was close. She moaned, and Holtz looked up, her eyes alight with expectation – and then she was gone.

Erin's orgasm shuddered out of her. It was easier the second time around, on her muscles at least, but she felt the force of it rushing right out to her fingers and toes, filling every part of her with tingling warmth. It felt as though her skin was on fire, every inch of her burning as the culmination of pleasure swept over her. She felt herself clench around the dildo again and again, even after the rest of her had fallen limp against the bed, the aftershocks carrying on even as the machine stilled and Holtz kissed her deeply.

“That was amazing,” Holtzmann said, stroking her hair as she whispered into her ear. “You're amazing.”

“Why thank you,” Erin said, but her voice was too shaky for real sarcasm. “That's… quite a machine you've got there.”

“You ready to call it a day?”

Erin chuckled. “ _Yes_.”

Erin winced with over-sensitivity as the dildo and the other attachments pulled away from her, leaving her achy and hollow-feeling. It was only once the attachments were clear that Holtz finally untied the straps holding Erin down. There were large red marks across her stomach and thighs, which wasn't surprising since the straps had probably been the only thing holding her on the bed at times. She suspected she was going to have some fairly distinctive bruises in the morning.

“Can you stand?”

“Yeah, sure, I'll manage,” Erin said, sounding more confident than she felt. She was still shaking slightly, and her thighs were stiff from being held open – not to mention that her whole pussy was glowing white-hot with sensitivity.

Carefully, she pushed herself until she was sat upright, swinging her legs over the side of the bed. But when her first step wobbled, Holtz was there, putting an arm around her to keep her steady.

“Come on, champ,” Holtz said. “On the bed.”

Erin tried to lie down, but Holtz wouldn't let her. Instead, she propped Erin against the pillow and handed her a cup of some bright orange liquid.

Holtz laughed when she saw Erin's nervous expression.

“It's Lucozade,” she explained. “You need to hydrate. Drink up.”

While Erin sipped her drink, Holtz joined her on the other side of the bed. Erin leaned against her shoulder, needing the skin contact. Holtz put an arm around her.

“You okay?” Erin asked.

“I am _spectacular_!”

“No, I mean…” Too tired to find the words, Erin gestured vaguely at Holtz's crotch.

“Oh.” Holtz chuckled. “Nah, I'm fine. I mean, my panties are soaked, but I'm good for now. How about you? Do you want to wash off before nap-time, or…?”

Erin drained the cup of Lucozade and put it down before snuggling deeper into the covers.

“No,” she said. “Nap first. Then shower. And then…”

Holtz wrapped an arm around her, spooning up close beside her. The scrape of her clothes against Erin's bare skin felt jarringly strange, and yet somehow perfect – and wasn't that just their relationship all over?

“Then?” Holtz prodded.

Erin smiled to herself.

“Then I think you need to teach me how that control panel works.”


End file.
